Peatlands, already dwindling, could face further losses

Typography

Tropical peat swamp forests, which once occupied large swaths of Southeast Asia and other areas, provided a significant “sink” that helped remove carbon dioxide from the atmosphere. But such forests have been disappearing fast due to clear-cutting and drainage projects making way for plantations. Now, research shows peatlands face another threat, as climate change alters rainfall patterns, potentially destroying even forested peatlands that remain undrained.

The net result is that these former carbon sinks, which have taken greenhouse gases out of the atmosphere, are now net carbon sources, instead accelerating the planet’s warming.

Tropical peat swamp forests, which once occupied large swaths of Southeast Asia and other areas, provided a significant “sink” that helped remove carbon dioxide from the atmosphere. But such forests have been disappearing fast due to clear-cutting and drainage projects making way for plantations. Now, research shows peatlands face another threat, as climate change alters rainfall patterns, potentially destroying even forested peatlands that remain undrained.

The net result is that these former carbon sinks, which have taken greenhouse gases out of the atmosphere, are now net carbon sources, instead accelerating the planet’s warming.

The findings are described this week in the journal Proceedings of the National Academy of Sciences, in a paper by MIT Professor Charles Harvey, research scientist Alexander Cobb, and seven others at MIT and other institutions.

“There is a tremendous amount of peatland in Southeast Asia, but almost all of it has been deforested,” says Harvey, who is a professor of civil and environmental engineering and has been doing research on that region for several years. Once deforested and drained, the peatland dries out, and the organic (carbon-containing) soil oxidizes and returns to the atmosphere. Sometimes the exposed peat can actually catch fire and burn for extended periods, causing massive clouds of air pollution.

Continue reading at Massachusetts Institute of Technology

Photo: Courtesy of the researchers